Laser sensor with flourescent loaded transparent plastic

ABSTRACT

A sensor for a laser may contain an at least partially transparent plastic with a fluorescent material that receives laser light at one frequency and creates light inside the transparent plastic with a second, different frequency. The light at the second frequency may travel through the plastic to an electronic sensor mounted against the transparent plastic. The sensor may be several feet in length or longer and still detect a single impinging Class I or Class II laser beam. In systems where the position of the laser may be known, a set of linear gain coefficients may be determined to calibrate the electronic sensor, as the signal strength of a received signal may decay with the distance from the electronic sensor to the location where the laser beam impinges the plastic element.

BACKGROUND

Lasers have many uses, including detecting the presence or absence ofobjects by detecting when a laser beam is received by a sensor. A lasertransmitter may send the laser beam across a void to a sensor. When thelaser beam is received by the sensor, there is no opaque object inbetween. When the laser beam is not received by the sensor, an objectmay be present. Another reason why the laser beam may not be receivedmay be that the laser or its sensor have been misaligned or maladjusted.

A fixed laser beam may sense the presence or absence of an object usinga straight beam of light. Such a sensor only detects the presence orabsence along a line from the laser source to the sensor. A scanning ormoving laser may be deployed to scan a planar or three dimensional area,provided that a sensor is able to detect the laser beam in the areasbeing scanned.

The alignment and calibration of a laser transmitter and receiver can bea tedious operation in some cases. In some hostile environments, thelasers or their sensors may be bumped, moved, or otherwise may bemisaligned, which may inadvertently cause the laser to not be received.When such a condition is found, a technician may be dispatched torealign and test the system, then place it back in service.

SUMMARY

A sensor for a laser may contain an at least partially transparentplastic with a fluorescent material that receives laser light at onefrequency and creates light inside the transparent plastic with asecond, different frequency. The light at the second frequency maytravel through the plastic to an electronic sensor mounted against thetransparent plastic. The sensor may be several feet in length or longerand still detect a single impinging laser beam. In systems where theposition of the laser may be known, a set of linear gain coefficientsmay be determined to calibrate the electronic sensor, as the signalstrength of a received signal may decay with the distance from theelectronic sensor to the location where the laser beam impinges theplastic element.

A two dimensional scanning laser system may automatically detect alaser, then align and calibrate itself to scan over the sensor area. Thesystem may have a laser with a controller that may cause the laser to bedirected over two dimensions, as well as a sensor apparatus. The lasermay be controlled with a mirror system that may pivot in two directions,thus allowing the laser to be scanned over a two dimensional area. Thesensor may be a point sensor, where the laser may be positioned in aconstant direction, as well as a larger area sensor where the laser maybe moved across the sensor area to detect objects in a two or threedimensional space. An alignment and calibration sequence may cause thelaser to scan across its operational area and detect the location of oneor more sensors.

This Summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used to limit the scope of the claimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings,

FIG. 1 is a diagram illustration of an embodiment showing an explodedview of a sensor device.

FIG. 2 is a diagram illustration of an embodiment showing a networkenvironment with controllable and steerable lasers and sensors.

FIG. 3 is a diagram illustration of an embodiment showing a section viewof a laser sensor.

FIG. 4 is a diagram illustration of an embodiment showing a severalexamples of sensor shapes.

FIG. 5 is a diagram illustration of an embodiment showing a steerablelaser that is controllable in two dimensions.

FIG. 6 is a diagram illustration of an embodiment showing scanning by asteerable laser to detect a sensor.

FIG. 7 is a diagram illustration of an embodiment showing a second passscan of a steerable laser to detect a sensor.

FIG. 8 is a diagram illustration of an embodiment showing calibrationpoints and operational path of a laser sensor.

FIG. 9 is a flowchart illustration of an embodiment showing a method forscanning an operational area of a laser to detect a sensor.

FIG. 10 is a flowchart illustration of an embodiment showing a methodfor calibrating a laser sensor.

FIG. 11 is a flowchart illustration of an embodiment showing a methodfor normal or production uses of a laser sensor.

FIG. 12 is a diagram illustration of an embodiment showing anenvironment with controllable lasers.

DETAILED DESCRIPTION Laser Sensor with Fluorescent Loaded TransparentPlastic

A laser sensor may incorporate a fluorescent material in a transparentplastic component. The fluorescent material may be excited by animpinging laser beam, then create a different wavelength of light insideof the plastic component. The light may then propagate within theplastic component where it can be sensed using an electronic sensor.

The laser sensor may operate by using the plastic component as a lightpipe to conduct light from a location where a laser beam impinges thecomponent to a sensor that may be located on an edge of the plasticcomponent. The plastic component may be a planar sheet plastic material,which may be curved, bent, molded, or shaped in various forms, or may beused as a flat sheet in a sensor.

The fluorescent material in the plastic component may cause a change inthe color or frequency of the impinging light. The laser beam may begreen, red, or other color, and the fluorescent material may becomeexcited by the laser light, then emit orange, pink, blue, green, orother color light. The second frequency may be selected by thefluorescent doping of the plastic, and may be selected to correspondwith an electronic sensor, which may be a photodiode, photoresistor, orother type of light sensor.

The laser sensor may be fabricated from a fluorescent doped plasticmaterial, an electronic sensor, and various mounting or protectinghardware. The sensor may include a protective transparent sheet, whichmay be frosted in some cases. The electronic sensor may have variouselectronic circuitry that may provide other functionality, such as gainadjustment.

The laser sensor may be configured in many shapes and sizes. Such asensor may be small, such as 0.25 in diameter or smaller, or may belarge, such as versions that are several feet or more in size. Oneversion of the sensor may be elongated to detect a laser beam that maymove in a linear motion may be sensed along the entire path of motion.

Laser Alignment and Calibration System for Scanning Lasers

A laser alignment system may have a one or two dimensional directionalcontrol that may be used to locate and align to a sensor and calibratethe signal strength at the sensor. The system may scan a laser beam overits operational area to detect the presence and location of sensors inthe operational area. The system may also calibrate itself to achieve aconsistent signal level when a laser impinges a sensor, regardless ofthe location of the impingement.

The laser alignment system may use a laser transmitter that may beoutfitted with a mirror or set of mirrors that may rotate in one or twodimensions. The rotation may be controlled to point the laser beam invarious locations, all of which may be under programmatic control. Acontroller may cause the laser beam to move anywhere within anoperational area, which may be defined by a cone, pyramid, or othervolume in which the laser may be oriented.

A controller may perform an alignment and calibration sequence inseveral steps. The controller may cause the laser to scan across theoperational area to identify any sensors within the operational area.The controller may be connected to the sensors and may receive signalsfrom the sensors. As each sensor is identified, the controller mayrecord the position of the laser beam, thereby creating a map of thesensors.

The controller may search for sensors in multiple passes. In a firstpass, the general locations of various sensors may be identified. In asecond pass, a finer grained location may be determined. In such asystem, a first pass may be performed by scanning quickly and with widergaps between scan lines, while the second pass may be slower and withnarrower gaps between scan lines, but may be performed only in the areaswhere a sensor was detected. Such systems may be useful when sensors areoddly shaped or when higher precision is desired, for example.

A calibration operation may be performed by comparing the measuredsignal strength from a sensor at one or many locations across thesensor. The calibration operation may include various mechanisms tonormalize or calibrate the incoming signal to detect the presence orabsence of a laser on the sensor. In some cases, the laser may beoperated in a lower power mode or pulsed to generate a detected signallevel closer to a predefined threshold.

Some sensors may generate different signal strength based on where thelaser impinges the sensor. In such cases, the signal strength may benoted for different locations across the sensor, and a mathematicalfunction may be computed to detect an offset or gain that may be appliedat various locations. Such functions may be linear or nonlinear.

Throughout this specification and claims, a laser is used as anexemplary light source that may be sensed using a sensor. In some cases,the light source may be a focused light source, light beam, collimatedor non-collimated light source, laser, or other source of light.

Throughout this specification, like reference numbers signify the sameelements throughout the description of the figures.

In the specification and claims, references to “a processor” includemultiple processors. In some cases, a process that may be performed by“a processor” may be actually performed by multiple processors on thesame device or on different devices. For the purposes of thisspecification and claims, any reference to “a processor” shall includemultiple processors, which may be on the same device or differentdevices, unless expressly specified otherwise.

When elements are referred to as being “connected” or “coupled,” theelements can be directly connected or coupled together or one or moreintervening elements may also be present. In contrast, when elements arereferred to as being “directly connected” or “directly coupled,” thereare no intervening elements present.

The subject matter may be embodied as devices, systems, methods, and/orcomputer program products. Accordingly, some or all of the subjectmatter may be embodied in hardware and/or in software (includingfirmware, resident software, micro-code, state machines, gate arrays,etc.) Furthermore, the subject matter may take the form of a computerprogram product on a computer-usable or computer-readable storage mediumhaving computer-usable or computer-readable program code embodied in themedium for use by or in connection with an instruction execution system.In the context of this document, a computer-usable or computer-readablemedium may be any medium that can contain, store, communicate,propagate, or transport the program for use by or in connection with theinstruction execution system, apparatus, or device.

The computer-usable or computer-readable medium may be, for example butnot limited to, an electronic, magnetic, optical, electromagnetic,infrared, or semiconductor system, apparatus, device, or propagationmedium. By way of example, and not limitation, computer readable mediamay comprise computer storage media and communication media.

Computer storage media includes volatile and nonvolatile, removable andnon-removable media implemented in any method or technology for storageof information such as computer readable instructions, data structures,program modules or other data. Computer storage media includes, but isnot limited to, RAM, ROM, EEPROM, flash memory or other memorytechnology, CD-ROM, digital versatile disks (DVD) or other opticalstorage, magnetic cassettes, magnetic tape, magnetic disk storage orother magnetic storage devices, or any other medium which can be used tostore the desired information and which can accessed by an instructionexecution system. Note that the computer-usable or computer-readablemedium could be paper or another suitable medium upon which the programis printed, as the program can be electronically captured, via, forinstance, optical scanning of the paper or other medium, then compiled,interpreted, of otherwise processed in a suitable manner, if necessary,and then stored in a computer memory.

When the subject matter is embodied in the general context ofcomputer-executable instructions, the embodiment may comprise programmodules, executed by one or more systems, computers, or other devices.Generally, program modules include routines, programs, objects,components, data structures, etc. that perform particular tasks orimplement particular abstract data types. Typically, the functionalityof the program modules may be combined or distributed as desired invarious embodiments.

FIG. 1 is a diagram illustration showing an exploded view of anembodiment 100 of a sensor. The sensor is illustrated in perspectiveview and shows some of the components of the sensor. Embodiment 100 isnot to scale.

A collector 102 may be a sheet material that is translucent plastic witha fluorescent doping or additive. The fluorescent material may beexcited by an incident laser and create light internal to the collectorthat is a different frequency than the laser. The light from thefluorescent material may remain largely trapped inside the collector 102and may be sensed by a photoelectric sensor 110 that may collect thelight through a sensor mounting surface 112.

The laser light may impinge the sensor through an incident surface 108,cause the fluorescent material to be excited, which generates a secondfrequency of light. The second frequency of light may propagate throughthe collector 102 to the photoelectric sensor 110. The photoelectricsensor 110 may be connected to a printed circuit board 114 and transmita signal through a network connection 116.

The light generated by the fluorescent material may be a color orfrequency that more closely matches the photoelectric sensor 110 thanthe incident laser beam. In some cases, the laser light frequency may beoutside the detectability range of the photoelectric sensor 110 or maybe only marginally detectable by the photoelectric sensor 110. Byconverting the incoming laser light at one frequency to light of asecond frequency by the fluorescent material, the sensor may have moredynamic range and have improved sensitivity to light frequencies thatwere previously difficult to sense. Such a system may allow for adifferent set of photoelectric sensors to be used in sensing lasers thatwere previously not applicable.

The fluorescent material may be used to convert incoming red, green,blue, or other color laser light to orange, yellow, red, pink, green,blue, or other light. In some cases, the laser light or other lightsource may be invisible infrared or ultraviolet light.

An escutcheon 104 may be an outer cover that may serve as a decorativeor protective exterior element. In some cases, the escutcheon 104 mayserve as a mounting mechanism. The escutcheon 104 may have an opening106 through which a laser may pass and impinge on the incident surface108 of the collector 102.

The printed circuit board 114 may include various circuitry in differentdesigns. In one design, the printed circuit board 114 may have acontroller that may control the operations of a steerable andcontrollable laser. In another design, the printed circuit board 114 maycontain circuitry that converts an analog signal from the photoelectricsensor 110 to a digital output that may be communicated across anetwork. Such a design may also include a controller that maycommunicate using a network protocol, such as TCP/IP or othercommunications protocol. Such systems may include a controller thatresponds to queries in a pull-type communication as well as a controllerthat transmits changes in detected levels in a push-type communication.

In some cases, the printed circuit board 114 may produce an analogelectrical signal that may be further sensed and processed.

FIG. 2 is a diagram of an embodiment 200 showing components that maycontrol and sense laser beams. The components are illustrated in anarchitecture that may have a central controller that may control severaldifferent laser and sensor combinations. One such example of a systemmay be a game system where the lasers may be used as obstacles in amaze. A figure presented later in this specification may illustrate asecond architecture of a system that has a direct connection between alaser and a sensor, as opposed to the networked version illustrated inembodiment 200.

The diagram of FIG. 2 illustrates functional components of a system. Insome cases, the component may be a hardware component, a softwarecomponent, or a combination of hardware and software. Some of thecomponents may be application level software, while other components maybe execution environment level components. In some cases, the connectionof one component to another may be a close connection where two or morecomponents are operating on a single hardware platform. In other cases,the connections may be made over network connections spanning longdistances. Each embodiment may use different hardware, software, andinterconnection architectures to achieve the functions described.

Embodiment 200 illustrates a device 202 that may have a hardwareplatform 204 and various software components. The device 202 asillustrated represents a conventional computing device, although otherembodiments may have different configurations, architectures, orcomponents.

In many embodiments, the device 202 may be a server computer. In someembodiments, the device 202 may still also be a desktop computer, laptopcomputer, netbook computer, tablet or slate computer, wireless handset,cellular telephone, game console or any other type of computing device.In some embodiments, the device 202 may be implemented on a cluster ofcomputing devices, which may be a group of physical or virtual machines.

The hardware platform 204 may include a processor 208, random accessmemory 210, and nonvolatile storage 212. The hardware platform 204 mayalso include a user interface 214 and network interface 216.

The random access memory 210 may be storage that contains data objectsand executable code that can be quickly accessed by the processors 208.In many embodiments, the random access memory 210 may have a high-speedbus connecting the memory 210 to the processors 208.

The nonvolatile storage 212 may be storage that persists after thedevice 202 is shut down. The nonvolatile storage 212 may be any type ofstorage device, including hard disk, solid state memory devices,magnetic tape, optical storage, or other type of storage. Thenonvolatile storage 212 may be read only or read/write capable. In someembodiments, the nonvolatile storage 212 may be cloud based, networkstorage, or other storage that may be accessed over a networkconnection.

The user interface 214 may be any type of hardware capable of displayingoutput and receiving input from a user. In many cases, the outputdisplay may be a graphical display monitor, although output devices mayinclude lights and other visual output, audio output, kinetic actuatoroutput, as well as other output devices. Conventional input devices mayinclude keyboards and pointing devices such as a mouse, stylus,trackball, or other pointing device. Other input devices may includevarious sensors, including biometric input devices, audio and videoinput devices, and other sensors.

The network interface 216 may be any type of connection to anothercomputer. In many embodiments, the network interface 216 may be a wiredEthernet connection. Other embodiments may include wired or wirelessconnections over various communication protocols.

The software components 206 may include an operating system 218 on whichvarious software components and services may operate.

A controller application 220 may control the operations of variouslasers and sensors. The controller application 220 may setup andcalibrate the lasers and sensors using a setup mode 222, then transitionto an operational or production mode 224 after calibration is complete.

The setup mode 222 may operate in two different phases. In a firstphase, a steerable laser system may scan its operational area to detectthe location of a sensor within its operational area. Once the locationis determined, a calibration phase may set the power level, sensorsensitivity, or make other calibrations so that the laser's presence orabsence may be detected with a predefined sensitivity.

The setup mode 222 may generate a set of locations in a steerablelaser's operational area where a sensor exists. These locations may bestored in a location database 226. When the setup mode 222 performscalibrations, the offsets or calibration constants may be stored in anoffset database 228.

A network 230 may connect the controller device 202 to various othercomponents, including steerable laser transmitters 232, fixed mountedlaser transmitters 250, and laser sensors or receivers 256. The network230 may be any mechanism by which the various devices may communicate.In some cases, the network 230 may be direct, hardwired connectionsbetween the controller device 202 and the various other components. Inother cases, the network 230 may be an Ethernet or other shared resourcefor multiple devices to communicate.

The steerable laser transmitters 232 may have a laser controller 234that may take commands issued from the controller application 220 andoperate a controllable laser 236, as well as a first axis 238 and secondaxis 234.

The controllable laser 236 may be a laser that the laser controller 234may turn on and off. In some cases, the controllable laser 236 may becontrollable to be turned on and off or modulated with a high frequency,and such frequencies may be multiple hertz, kilohertz, megahertz, orother ranges. The laser output may be controllable in amplitude oroverall power level. Then the laser is controllable in power level,frequency, or other ways, the laser output may be calibrated such that areceiving sensor may receive the laser beam above but near a decisionthreshold. The decision threshold may be the received level that isdefined as the boundary between detecting the presence of the laser.When the received level is above the boundary, the laser is detected asbeing present. When the received level is below the boundary, the laseris detected as not being present.

The sensitivity of the sensing system may be a function of how muchmargin or offset is between the normally on signal level and thedecision threshold. When the sensitivity is too high and the marginbetween the normal signal level is too small, a very slight interruptionor degradation of the laser signal may cause the sensor to be tripped.In a game situation, the use of fog or other elements in a game systemmay cause the laser signal to be attenuated, and setting the sensitivitytoo high may have unintended tripped sensors.

When the sensitivity is too low and the margin between the normal signallevel is too large, the laser may be partially interrupted withoutcausing the sensor to trip. Such a setting may not detect properly whenthe laser emits some spray or be partially diffused, as the main part ofthe laser beam may be interrupted but the spray may still transmitenough signal not to trip the sensor.

The first axis 238 and second axis 244 may be controllable axes that maydirect the laser beam along two different arcs. In a typical deployment,a mirror may be mounted on a two dimensional rotating gimbal with eachaxis being separately controlled. The first axis 238 may have anactuator 240 and a feedback sensor 242, and the second axis 244 may havean actuator 246 and a feedback sensor 248.

The first axis 238 and second axis 244 may be controllable by the lasercontroller 234 to move the laser to an input ‘location’, which may bedefined by a position of the first axis and a position of the secondaxis. The location may be captured by the respective feedback sensors242 and 248. The actuators 240 and 246 may be stepper motors, servomotors, or some other type of actuator. The feedback sensors 242 and 248may be any type of linear or angular distance transducer.

The laser controller 234 may be capable of communicating with thecontroller device 202 over the network 230. The controller device 202may be able to send commands to the laser controller 234 to turn on thelaser, set the laser's power and other attributes, as well as cause thelaser to be pointed in a given location. The laser controller 234 mayfurther be capable of two way communication, where the controller device202 may be able to query the laser controller 234 about status,identification, and other information, and the laser controller 234 maybe capable of responding to such queries.

A fixed mounted laser transmitter 250 may be controlled by thecontroller device 202. The fixed mounted laser transmitters 250 may besimilar to the steerable laser transmitters 232, but where the directionof the laser may be manually configured and may not be underprogrammatic control. A fixed mounted laser transmitter 250 may have alaser controller 252 along with a controllable laser 254. Thecapabilities of the controllable laser 254 may be similar to thosedescribed for the controllable laser 236, and the capabilities of thelaser controller 252 may be similar to those described for the lasercontroller 234.

The laser receivers 256 may have a sensor 258 and an adjustable gainsystem 260. The sensor 258 may be similar to the sensor described inembodiment 100. the adjustable gain system 260 may be electronics orother circuitry that may be programmable or changeable to adjust thegain of the output when a laser impinges on the sensor 258.

FIG. 3 is a diagram illustration of an embodiment 300 showing a sectionview of a sensor with a diffuser. Embodiment 300 is not to scale.

The sensor 302 may have an escutcheon 304, a diffuser 306, and acollector 308. The escutcheon 304 may serve as a mounting device as wellas an aesthetic and protective cover to the sensor 302. A color filter326 may serve to filter incoming light, and a reflector 328 may helpcapture additional light that may have passed through the collector 308.

A diffuser 306 may be a translucent sheet material that may be frostedor have some other diffusing pattern. The diffuser 306 may scatter anincoming laser beam so that the scattered laser beam may impinge a widearea of the collector 308. In such cases, a larger amount of fluorescentmaterial may be excited in the collector 308 than in embodiments wherethe diffuser 306 may not be present.

The diffuser 306 may further serve as a protective layer that mayprevent damage to the collector 308 when the sensor is in service.

A color filter 326 may filter the incoming light to allow light within apredetermined color or set of frequencies to pass through the colorfilter 326 and illuminate the collector 308. The color filter 326 maypass colors or frequencies that may excite material in the collector 308and may not pass light at other frequencies that may or may not excitethe collector 308. In many cases, the color filter 326 may be selectedto pass light at the same or similar colors or frequencies as the laseror other light source that is to be detected, while rejecting or notpassing light at other colors or frequencies.

The color filter 326 may be useful when attempting to detect a lightsource with a known and predetermined color or frequency. One examplemay be to use a green color filter 326 to sense a green laser beam, andwhere the green color filter 326 may screen out ambient light. Such afilter may increase the sensor's detection when used in situations whereambient and other light sources are present.

The color filter 326 may be a sheet of translucent material thatcontains a colorant, such as a colored polycarbonate sheet. In somecases, the color filter 326 may be a film, coating, or other type offilter that may be applied to the diffuser 306, collector 308, or someother component.

The collector 308 may have an incident surface 310, which may be thesurface through which a laser beam may impinge on the collector 308. Anopposite surface 312 may be parallel to the incident surface 310. Inmany embodiments, the incident surface 310 and opposite surface 312 maybe polished surfaces. The polished surfaces may serve to reflect thelight internally generated by the excited fluorescent material and allowthe light to propagate to a photoelectric sensor 320.

A reflector 328 may be placed behind the opposite surface 312. Thereflector 328 may be a mirror or other material that may reflect backany light that may have passed through the collector 308. In some cases,the reflector 328 may increase the sensor's ability to gather low levelsof light that may impinge the incident surface 310.

The collector 308 may be mounted with an air gap 314 between thediffuser 306 and the incident surface 310. The air gap 314 may preventlight from the collector 308 to propagate into the diffuser 306. The airgap 314 may be achieved by using mounting spacers 316 to create adistance 318. In many cases, the distance 318 may be as small as 0.050in or smaller, although gaps or 1/16 in, ⅛ in, ¼ in, ⅜ in, or larger mayalso be used. In some embodiments, some or all of the components of thesensor may be assembled without air gaps such as the air gap 314.

Embodiment 300 illustrates three sets of spacers 316, each providing asimilar air gap 314 between the various components, such as the diffuser306, color filter 326, collector 308, and reflector 328. In otherembodiments, different sized spacers may be used between each of thevarious components. For example, a larger air gap may be providedbetween the diffuser 306 and the color filter 326, and a smaller air gap(or none at all) may be provided between the color filter 326 and thecollector 308.

The photoelectric sensor 320 may also be mounted a distance 322 from thecollector 308. In many cases, the distance 320 may be as small as 0.050in or smaller, although gaps or 1/16 in, ⅛ in, ¼ in, ⅜ in, or larger mayalso be used. In some cases, the photoelectric sensor 320 may be incontact with the collector 308. In still other cases, a sensingcomponent of the photoelectric sensor 320 may be installed into a hole,recess, countersink, or other indentation into the collector 308.

In some cases, the photoelectric sensor 320 may be mounted with a clearor translucent bonding agent that may fuse, glue, pot, or otherwiseconnect the photoelectric sensor 320 with the collector 308.

The photoelectric sensor 320 may have an electrical connection 324 to aprinted circuit board, network connection, controller, or other devicenot shown.

FIG. 4 is a diagram illustration of an embodiment 400 showing severalsamples of sensor shapes. Embodiment 400 is not to scale. The examplesof shapes may illustrate sensors that may capture a laser beam that maybe moved across different points of the sensor to form a movement path.Such a movement path may be used with a steerable laser transmitter todirect the laser along the path, all the while being able to determinethat the laser is impinging on a collector and being able to detect whenthe laser beam is broken.

A sensor 402 may illustrate a long, thin sensor where a laser maytraverse a straight line. The sensor 402 is illustrated with an incidentsurface 404 and an escutcheon 406. The sensor 402 may have a length 408which may be any length. In some cases, the length 408 may be severalinches, feet, yards, or more in length.

The length 408 may be 1 in, 2 in, 3 in, 4 in, 6 in, 8 in, 12 in, 24 in,36 in, 48 in, or longer. The other example sensors in embodiment 400 mayhave similar sizes.

The sensor 410 may be a circular sensor that may have a center opening416. The sensor 410 is illustrated with an incident surface 412 and anescutcheon 414. The sensor 410 may be used by having a laser beamtraverse the circular path of the incident surface 412.

The sensor 418 may illustrate a sensor that has a winding path. Anincident surface 420 is illustrated with an escutcheon 422. The sensor418 may be used by having a laser traverse the path of the incidentsurface 412.

The sensors illustrated in embodiment 400 may be planar or may beformed, shaped, molded, or otherwise have three dimensional contours,including three dimensional contours in the various incident surfaces.

FIG. 5 is a diagram illustration of an embodiment 500 showing a lasercontrollable or steerable in two dimensions. Embodiment 500 is not shownto scale.

The laser system 502 may have a laser 504, which may be fixed mountedand may be directed at a mirror 506. The mirror 506 may be mounted on atwo-axis gimbal 518, which may be moved and monitor by a first axisactuator 510 and a first axis sensor 512, as well as a second axisactuator 514 and a second axis sensor 516.

The steerable or controllable laser system 502 may have the capabilitiesdescribed for the steerable laser transmitters 232 in embodiment 200,and may be merely one example of such a laser transmitter.

In some embodiments, a two-mirror system may be used. A two-mirror mayhave one mirror that can be moved in one dimension while a second mirroris moved in a different dimension. Such a system may be controlled in asimilar manner as the gimbal design illustrated in embodiment 500. Othercontrollable or steerable light sources may also be used.

FIG. 6 is a diagram illustration of an example embodiment 600 showingoperations of a steerable laser system for scanning to detect a sensor.Embodiment 600 shows a scan path of a laser where the laser may bescanned over its entire operational area and may detect a sensorsurface.

An incident surface of a sensor 602 is illustrated. A steerable lasermay be mounted such that the operational area of the laser may overlapthe sensor. The operational area may be defined by the controllable arcsin which a steerable laser may be directed, such as the steerable laserof embodiment 500.

A scan path 606 may start at one corner of the operational area with abeginning point 604. From the beginning point 604, the laser maytraverse one axis, increment along the second axis, and traverse againalong the first axis. Such a system may scan across the entireoperational area of the laser.

As the scanning takes place, a controller may record when the sensor 602is detected and when the sensor is not detected. For example, thescanning may occur until point 608 where the sensor is detected. As thescanning continues, the point 610 may be where the sensor 602 is nolonger detected. The scanning may continue past points 612 and 614,where the sensor may again be detected then no longer detected. At eachtransition point, a controller may capture and save the location of thepoint.

The scanning illustrated by the path 606 may represent a first passacross the operational area of a laser. The first pass may identifymultiple transition points. A rough approximation of the incidentsurface of the sensor 602 may be determined from such a first pass. Acalculation may be performed to determine a midpoint or centroid of anarea for the sensor 602.

The mechanism of embodiment 600 may illustrate one method by which acontroller may automatically identify a sensor and align itself to pointtowards the sensor. In some cases, the laser may be programmed to pointat the center of the

Some systems may determine a movement path for a laser, where the lasermay scan back and forth from one end of the path to the other. Such apath may be calculated based on the operational area of the sensor.

FIG. 7 is a diagram illustration of an example embodiment 700 showing anexample method for second pass scanning. The example of embodiment 700may be a second pass operation that may follow a first pass scan ofembodiment 600.

The incident surface of a sensor 702 is shown, similar to that ofembodiment 600. From the scan illustrated in embodiment 600, an outline704 may be identified that is some distance larger than the transitionpoints detected in embodiment 600.

A starting location 706 is selected and the laser may be moved along ascan path 708. In the example of embodiment 700, the laser may scanuntil it encounters a transition point, then indexes a small distance ina second dimension, and reverses course until another transition pointis encountered.

The scan path 708 may follow the edge of an incident surface, all thewhile collecting more transition points and mapping the incident surface702. Such a scan method can be compared to the scan path 606 ofembodiment 600, which may scan across the entire operational area of thelaser. Some systems may use either method, a combination of bothmethods, or some other method to identify the incident surface 702 of asensor.

In some embodiments, the sensitivity of the edge detection may beenhanced by lowering the power level of the laser during the second scanillustrated in embodiment 700. A lower power level may heighten thesensitivity of the edge detection by decreasing the effects of scatterand overspray when sensing the laser near the edge of the incidentsurface 702.

FIG. 8 is a diagram illustration of an example embodiment 800 showing anincident surface 802 of a sensor and an operational path 808 for alaser. In the example of embodiment 800, a laser may be programmed toscan from location 804 to location 806 and back. Embodiment 800illustrates an example of an operational path 808 that may be defined bythree points. This illustration is merely to simplify the discussion.Other systems may have additional points along an operational path,sometimes with dozens, hundreds, or even thousands of points.

As a laser is moved from location 804 to location 806, a controller mayanalyze a signal from the laser sensor to determine if the laser beam isbroken or not. With some sensors, the signal received at location 804may be different from the signal received at location 806. For sensorssuch as the sensor of embodiment 100 that use fluorescent material, thesignal received near the photoelectric sensor may be higher than thesignal received at a point that is several inches or several feet fromthe photoelectric sensor. In such embodiments, the signal may becalibrated at multiple locations and a calibration function may becomputed.

For example, a laser may be trained at location 804 and a firstcalibration may be performed. A second calibration may be performed atlocation 806. From the two calibration operations, a calibrationfunction may be derived so that when the laser is pointed at location810, an offset or other calibration factor may be computed and appliedto the signal.

FIG. 9 is a flowchart illustration of an embodiment 900 showing a methodfor scanning the operational area of a steerable laser. The operationsof embodiment 900 may also be illustrated in the discussion ofembodiments 600 and 700.

Other embodiments may use different sequencing, additional or fewersteps, and different nomenclature or terminology to accomplish similarfunctions. In some embodiments, various operations or set of operationsmay be performed in parallel with other operations, either in asynchronous or asynchronous manner. The steps selected here were chosento illustrate some principals of operations in a simplified form.

Embodiment 900 illustrates a generalized method for scanning theoperational area of a laser and detecting transition points between whena laser is detected and not detected. When a laser may be used in asystem with human contact, such as a laser maze game, security system,or other system, the laser may be normally operated such that the laserturns off when the laser beam is not sensed. In the operations ofembodiments 600, 700, and 900, such a condition may be overridden suchthat the laser is kept on even when the laser is not detected. In suchcases, the operations of embodiment 900 may be performed automaticallywhen humans may be not present or when humans may have eye protection.

The scanning sequence may begin in block 902. The system may be set toits highest sensitivity and power levels in block 904. A calibrationroutine may be performed after scanning.

A starting point may be selected in block 906. In many cases, a startingpoint may be one corner of a rectangular operational area. A scan may bemade across a first dimension of the controllable laser's operationalarea in block 908.

While scanning in block 910, each location where the sensor transitionsfrom detecting or not detecting the laser is captured. If the scan hasnot fully incremented through the second dimension in block 912, thesecond dimension is incremented in block 914 and the process may returnto block 908 to perform another scan.

After scanning the full operational area in block 912, the transitionlocations may be consolidated into a detection area in block 914.

If the process is to be repeated for additional accuracy in block 916,the increment dimension may be adjusted to a smaller increment in block918 and a scan path may be determined in block 920 form the previoustransition points. The process may return to block 906 and another scanmay be performed.

When the desired accuracy is achieved in block 918, a sweep path may bedetermined from the detection area in block 924. The sweep path may be asingle path or circuit that may be traversed by the laser over thelength or path available on a given sensor, such as the examples ofembodiment 400 where a linear sensor, circular sensor, and a squigglypath sensor were illustrated. In cases where the sensor is small, thelaser may be pointed at a single point at the centroid or center of thedetected area.

The scanning sequence may end in block 926.

FIG. 10 is a flowchart illustration of an embodiment 1000 showing amethod for calibrating a laser system, such as described in embodiment800. The operations of embodiment 1000 may illustrate one method bywhich several calibration points may be evaluated and calibrationconstants or offset values may be calculated. After calibrating thesensor system at two or more points, a calibration function may bedetermined so that calibration constants may be calculated for otherlocations in a sensing area.

Other embodiments may use different sequencing, additional or fewersteps, and different nomenclature or terminology to accomplish similarfunctions. In some embodiments, various operations or set of operationsmay be performed in parallel with other operations, either in asynchronous or asynchronous manner. The steps selected here were chosento illustrate some principals of operations in a simplified form.

A calibration sequence may begin in block 1002.

Calibration points may be identified in block 1004. In some cases, thecalibration points may be endpoints of a path that a laser may traversein a scanning laser system. Some cases may use multiple points within asensor's incident area, such as midpoints or other locations within ascan path.

Each calibration point may be evaluated in block 1006. For each point inblock 1008, the laser may be aimed at the point in block 1010. Ameasured signal may be received in block 1012 indicating that the laseris received.

An offset value may be calculated in block 1014. The offset value may bea difference from the measured signal to a predefined offset from adetection threshold. The detection threshold may be the signal level ofa transition from detected to not detected occurs. The predefined offsetmay be a tolerance or offset that increases the normal signal tocompensate for any noise or variation in the signal that can betolerated while still having the system detect the laser.

The system may be adjusted in block 1016 to compensate for the offsetvalue. The adjustments in block 1016 may be adjusting the energytransmitted by the laser, adjusting the gain applied to the receivedsignal, or a combination of both.

The laser energy level may be adjusted by adjusting the overall powerlevel in some cases. In some cases, the laser energy level may beadjusted by turning the laser on and off. In some such cases, a lasermay be turned on and off faster than can be detected by the human eye,such that a human may see a constant beam, but the beam may be cycled onand off. Because the beam may be cycled on and off, the effective powertransmitted to the sensor may be reduced, thereby calibrating thereceived signal to be at the desired offset level.

The calibration offsets may be stored in block 1016.

After analyzing each calibration point in block 1006, a function may bedetermined in block 1018 from which calibrated offset values may bedetermined for other locations in the scan area.

The calibration sequence may end in block 1020.

FIG. 11 is a flowchart illustration of an embodiment 1100 showing amethod for scanning the operational area of a steerable laser in anormal or production operation. The normal or production uses of a lasersensor may detect the presence or absence of the laser signal bycomparing the received signal from a sensor and comparing the signalusing an offset determined from a calibration function, such as thecalibration function determined in block 1018 of embodiment 1000.

Other embodiments may use different sequencing, additional or fewersteps, and different nomenclature or terminology to accomplish similarfunctions. In some embodiments, various operations or set of operationsmay be performed in parallel with other operations, either in asynchronous or asynchronous manner. The steps selected here were chosento illustrate some principals of operations in a simplified form.

Normal operation may begin in block 1102.

A movement path may be determined in block 1104. The movement path mayhave been determined after a scanning function. In some cases, themovement path may be programmed into a controller using some othermechanism.

A start point may be selected in block 1106. The movement of the laseracross the sensor may begin in block 1108.

As the laser moves, a location may be determined in block 1110. Acalibration offset may be calculated in block 1112 and used to calibratea sensor signal. If the laser is sensed in block 1114, the motion maycontinue in block 1116 along the path and the method may return to block1110.

If the laser beam is detected to be broken in block 1114, the laser maybe turned off in block 1118 and an alert may be generated or otheraction taken in block 1120.

FIG. 12 is an example illustration of an embodiment 1200 showing a laserand sensor system in a network architecture. Embodiment 1200 mayillustrate many of the same components illustrated in embodiment 200,but with an architecture where the laser and sensors are connected toeach other through light transmission and electrical connections. Inembodiment 200, the lasers and sensors may be connected through anetwork. In such an embodiment, the lasers may be programmaticallyconnected to each other by assigning a particular laser to a particularsensor.

Embodiment 1200 may illustrate an architecture where a laser and sensorpair may be matched using hardware or other predetermined mechanism. Insome cases, a direct electrical connection may be made between a sensorand a laser controller. In other cases, the electrical connectionbetween a sensor and laser controller may still be made through anetwork or other connection.

In some applications, a laser controller may be capable of turning off alaser very quickly when the laser beam is not sensed by a sensor. In oneexample, a laser beam may be deployed to detect human beings may beconfigured to turn off the laser as quickly as possible when the beam isbroken. Such a deployment may turn off the laser beam within a matter ofmilliseconds from detecting a break in the beam, and may enable a lasersystem to be classified as a Class II laser system even when the lasersthemselves are Class III devices.

Embodiment 1200 shows a smart laser 1202 and a sensor 1204. The smartlaser 1202 may include a controller that may control a laser beamdirectionally as well as may be able to turn the laser on and off,adjust its power level, modulate the laser signal, and perform otheroperations. The smart laser 1202 may have a programmable controller thatmay perform many of the various operations, as well as may be connectedto a server computer over a network connection.

The smart laser 1202 may be illustrated as a stand alone hardwaredevice, but some embodiments may consist of multiple hardware componentsthat may be connected together.

A laser controller application 1206 may be a processor executingsoftware or other mechanism that may perform functions such as settingup the laser, detecting the sensor, determining and storing anoperational path for the laser, causing the laser to move, detectingwhether or not the laser is being received by the sensor, communicatingwith a server computer, and other functions.

The laser controller application 1206 may control the controllable laser1208, as well as one or more steerable axes 1210 and 1212. The lasercontroller 1206 may cause the controllable laser 1208 to illuminate andmay steer or direct the laser output towards the sensor 1204.

The sensor 1204 may include a photoelectric sensor 1214, which may beconnected to a programmable or adjustable gain 1216 and an electricaloutput 1218. The photoelectric sensor 1214 may be mounted in a sensorsuch as the sensor illustrated in embodiment 100 or some other sensormounting.

The electrical output 1218 of the sensor 1204 may be connected to thesensor input 1222 of the laser controller application 1206. In somecases, such a connection may be a direct, hardwired electricalconnection, although other cases may pass such a connection through anetwork or other connection.

When the electrical output 1218 of the sensor 1204 has a direct or otherhigh speed connection with the sensor input 1222, the smart laser 1202may be capable of detecting changes in light sensed by the photoelectricsensor 1214 in millisecond or sub-millisecond time frames. Such speedmay be sufficient to permit the laser controller application 1206 todetect that a laser beam has been broken and to turn off thecontrollable laser 1208 within the human blink reflex. In such a case,the smart laser 1202 may be classified as a Class II laser system.

The laser controller application 1206 may be connected to a servercomputer 1230 executing a controller application 1232 through a network1226 and a network connection 1224. The controller application 1232 maysend commands and receive information from the laser controllerapplication 1206 as part of a larger application. For example, a lasermaze application may have several smart laser 1202 and sensor 1204pairs, as illustrated by the laser/sensors 1228.

The foregoing description of the subject matter has been presented forpurposes of illustration and description. It is not intended to beexhaustive or to limit the subject matter to the precise form disclosed,and other modifications and variations may be possible in light of theabove teachings. The embodiment was chosen and described in order tobest explain the principals of the invention and its practicalapplication to thereby enable others skilled in the art to best utilizethe invention in various embodiments and various modifications as aresuited to the particular use contemplated. It is intended that theappended claims be construed to include other alternative embodimentsexcept insofar as limited by the prior art.

What is claimed is:
 1. A sensor device comprising: a collector: being atleast partially translucent; having an incident surface that receives alight beam; comprising a fluorescent doping that receives said lightbeam having a first frequency and generates light having a secondfrequency; a sensor mounting surface adjacent to said incident surface;a photoelectric sensor having a sensing element, said sensing elementbeing mounted in said sensor mounting surface, a diffuser adjacent tosaid incident surface, said diffuser having an air gap between saiddiffuser and said incident surface, and said diffuser having at leastone frosted surface.
 2. The sensor device of claim 1, said secondfrequency being a visible orange color.
 3. The sensor device of claim 2,said first frequency being a visible green color.
 4. The sensor deviceof claim 2, said first frequency being a visible red color.
 5. Thesensor device of claim 2, said first frequency being a non-visiblefrequency.
 6. The sensor device of claim 1, said incident surface havingat least one dimension in excess of 6 inches.
 7. The sensor device ofclaim 1, said incident surface having at least one dimension in excessof 12 inches.
 8. The sensor device of claim 1, said incident surfacehaving at least one dimension in excess of 24 inches.
 9. The sensordevice of claim 1, said incident surface having at least one dimensionin excess of 36 inches.
 10. The sensor device of claim 1, said incidentsurface being polished.
 11. The sensor device of claim 10, saidcollector having a second surface parallel to said incident surface,said second surface being polished.
 12. The sensor device of claim 1,said photoelectric sensor having a higher detection sensitivity for saidsecond frequency than said first frequency.
 13. The sensor device ofclaim 1 further comprising: an escutcheon having an opening, saidincident surface being visible to said light beam through said opening.14. The sensor device of claim 13, said photoelectric sensor beingcovered at least in part by said escutcheon.
 15. The sensor device ofclaim 1, said light beam being a laser beam.
 16. The sensor device ofclaim 1 further comprising a light filter.
 17. A sensor devicecomprising: a collector: being at least partially translucent; having anincident surface that receives a light beam; comprising a fluorescentdoping that receives said light beam having a first frequency andgenerates light having a second frequency; a sensor mounting surfaceadjacent to said incident surface; a photoelectric sensor having asensing element, said sensing element being mounted in said sensormounting surface, said sensor mounting surface being perpendicular tosaid incident surface and said photoelectric sensor being mounted withan air gap between said photoelectric sensor and said sensor mountingsurface.